1. Field of the Invention
This invention relates to testing devices and in particular to devices for testing conditions of soil.
2. Description of the Prior Art
A number of different watering and irrigation devices and systems have been developed for watering flowerpots and private gardens, watering trees, plants and greens of public squares, parks, driveways, highways, and irrigating horticulture and agriculture plots in hot and arid sections of countries. However, there has been no simple device or system which can be operated by any unexperienced layman to test, ascertain and maintain a desirable state of moisture in the soil at the mean depth where seeds are to be sown, or where plants absorb the nutrition dissolved in water moisture for their growth. A number of known devices use high resistance measurement, such as direct deflection method, capacitance method, Wheatstone bridge method, etc., to provide a highly accurate reading for use in scientific experimentations. However, such devices are heavy and cumbersome and not effectively adapted for testing an area from place to place. Furthermore, such systems can be operated only by highly trained, experienced people. It is interesting to note that studies had been made and facts are known for almost all important plants as to the mean depth where each plant collects and absorbs nutritious solution from the soil through its network of roots. For instance, the depth for begonia plants is 5 cm., gladiolus or amaryllis 7 cm., dahlia 13 cm., etc. There is presently no device which is simple in operation and handy to carry about for testing the ground moisture needed by plants. Without such an instrument, almost all watering or irrigation is done at random without any direct evidence that the watering operation is what is intended. Of course, without data of the water content in the soil where it is needed, no improvement can be made scientifically.
Since the temperature, humidity of air, and the rate of air current movement in the area concerned all affect the evaporation of water in the process of irrigation, it would be extremely difficult for even men of experience to control "watering" effectively accurately and without much waste. Furthermore, geological differences of soil in one area as compared with another, and differences of geographical contours make the different rates of flow of irrigation water in different areas. Accurate testing of ground moisture is essential for effective watering or irrigation to provide the desired growth of vegetable and plant life. This invention covers a device which is very simple in operation, readily carried by hand, effectively accurate, and economically useful for horticultural applications and home gardening.
With the use of the present device, experiment data can be readily accumulated for progressive improvement in the art of horticulture and agriculture.